title: Inhibition of the B cell by CD22: a requirement for Lyn.
abstract: Mice in which the Lyn, Cd22, or Shp-1 gene has been disrupted have hyperactive B cells and autoantibodies. We find that in the absence of Lyn, the ability of CD22 to become tyrosine phosphorylated after ligation of mIg, to recruit SHP-1, and to suppress mIg-induced elevation of intracellular [Ca2+] is lost. Therefore, Lyn is required for the SHP-1-mediated B cell suppressive function of CD22, accounting for similarities in the phenotypes of these mice.
authors.affiliation: Wellcome Trust Immunology Unit, Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, England CB2 2SP.
authors.forename: K G
authors.initials: KG
authors.lastname: Smith
authors.forename: D M
authors.initials: DM
authors.lastname: Tarlinton
authors.forename: G M
authors.initials: GM
authors.lastname: Doody
authors.forename: M L
authors.initials: ML
authors.lastname: Hibbs
authors.forename: D T
authors.initials: DT
authors.lastname: Fearon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology*; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D015815:Cell Adhesion Molecules; D007108:Immune Tolerance; D047908:Intracellular Signaling Peptides and Proteins; D037102:Lectins; D051379:Mice; D018345:Mice, Knockout; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000502:physiology*; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D051918:Sialic Acid Binding Ig-like Lectin 2; D015398:Signal Transduction; D013154:Spleen / Q000166:cytology; D019061:src-Family Kinases / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; C497868:Cd22 protein, mouse; D015815:Cell Adhesion Molecules; D047908:Intracellular Signaling Peptides and Proteins; D037102:Lectins; D011947:Receptors, Antigen, B-Cell; D051918:Sialic Acid Binding Ig-like Lectin 2; D019000:Phosphotyrosine; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C509248:Ptpn6 protein, mouse; D002118:Calcium